Apparatus for forming cavities in the wall of a socket of a pin-type glass insulator



June 14, 1955 J. E. WILCOCK 2,710,492

APPARATUS FOR FORMING CAVITIES IN THE WALL OF A SOCKET OF A PIN-TYPE GLASS INSULATOR Filed 001;. '27, 1952 4 Sheets-Sheet 1 Inventor gm 2' 7 l w y 2 WAitomey June 14, 1955 J E. wlLcocK 2,710,492

APPARATUS FOR I ORMING CAVITIES IN THE WALL OF A SOCKET OF A PIN-TYPE GLASS INSULATOR Filed Oct. 2'7, 1952 4 Sheets-Sheet 2 Inventor V A itorneys June 14, 19 55 J. E. WILCOCK 2,710,492

' APPARATUS FOR FORMING CAVITIES IN THE WALL OF A SOCKET OF A PIN-TYPE GLASS INSULATOR 7 Filed Oct. 27, 1952 4 Sheets-Sheet 5 June 14,1955 J. E. WILCOCK 2,710,492

' APPARATUS FOR FORMING CAVITIES IN THE WALL OF A SOCKET OF A PIN-TYPE GLASS INSULATOR Flled Oct 2'7, 1952 4 Sheets-Sheet 4 Attorney;

t ittes ZJNAQZ Patented June 14, 1%55 ice APPARATUS FOR Ffl RMiNG CAVITEES IN THE WALL OF A SGCKET F A PIN-TYPE GLASS INSULATGR John Edward Wilcock, St. Helerss, England, assigncr to Pilkmgton Brothers Limited, Liverpool, England, a corporation of Great Britain Application (Bctober 27, 1952, Serial No. 317,077

Claims priority, application Great Britain November 20, 1951 6 Claims. (Cl. 49-42) This invention relates to apparatus for forming cavities in the wall of a socket of a pin-type glass insulator while the glass body is in a hot plastic state. A pintype insulator, as is well understood, is one in which the conductor is carried on the top of the insulator so that there is little or no tendency for the locating pins to be pulled out of the insulator.

According to the present invention there is provided apparatus for forming cavities in the wall of the socket of a pin-type glass insulator whereby cement in the socket and surrounding the pin interlocks the pin with the insulator, comprising a structure settable on a lower mould part in which an insulator is formed, a pair of tong members pivotally supported by said structure for swinging movement and to extend beyond the opposite outer and inner sides of the structure, a swelling on the outside of the end of each tong member portion which extends beyond the inner side of said structure, a spring to urge apart the tong member portions having said swellings, an abutment disposed for co-operation with the tong member portions extending beyond the outer side of said structure, a rod carrying said abutment and supported for axial movement towards and away from said swellings thereby to permit and prevent sole control of the tong members by said spring, and adiustable stop means supported by said structure to determine the extent of swinging movement of the tong members under control of the spring.

In order that the invention may be clearly understood two embodiments thereof will now be described, by way of example, with reference to the accompanying diagrammatic drawings and in which:

Fig. 1 is an elevation, partly in section, of apparatus according to the invention and intended for manual manipulation,

Fig. 2 is a side view, partly in section, of Fig. 1, looking in the direction of the arrow A, Fig. 1,

Fig. 3 is a top plan of a part of Fig. 1,

Fig. 4 is an elevation, partly in section, of an alternative form of apparatus according to the invention, this apparatus being intended for automatic operation, and

Fig. 5 is a top plan of part of Fig. 4, the view being taken on the line VV, Fig. 4.

In the drawings, like references designate similar parts.

In Figures 1 to 3 of the drawings, there is illustrated an apparatus according to the invention which comprises a unitary structure capable of being manually lifted to and from co-operation with a lower mould part in which a glass body in a hot plastic state is being formed into an insulator.

The apparatus comprises a structure formed by a locating or cushioning ring 1 which, as illustrated in Fig. 1, is shaped to be settable on and to co-operate with the top of a lower mould part 2 in which is located a partly formed glass insulator 3 which has been shaped in operations prior to the placing of the apparatus according to the invention on the top of the mould part tit 2. To the locating ring 1 is secured a plate 4, the plate being retained in position relative to the locating ring by bolts 5 or other suitable means. The plate 4 is provided with a central aperture into which is fitted a bush 6 having a flange 7 between its ends so that a part of the bush protrudes from each side of the plate 4. The flange 7 is secured by bolts 8 or other suitable means to the plate 4.

A pair of tong members 9 extend through the bush 6 and their lower ends, that is the end portions thereof which extend beyond the inner side of the ring 1, have swellings 10 to form cavities 11 in the sockets 12 of an insulator. The tong members 9 are supported for swinging movement by a pivot pin 13 common thereto and extend through the bush 6 as can be most clearly seen in Figure 2, thereby to extend beyond the opposite outer and inner sides of the ring 1. The pin 13 is located relative to the bush 6 by a head 14 and a split pin 15, Figure 2.

As can be seen from the drawings, biasing means consisting of springs 16 operate on the upper ends 17 of the tong members to urge apart the lower ends thereof with the swellings 10.

During the introduction of the tong members 9 into the socket 12 of the glass body 3, and during their removal from the socket after the cavities have been formed therein, the lower ends of the tong members 9 are forced towards each other and are retained in this closed position, as illustrated in Figure 1, by an abutment 18 carried by a rod 19 and which cooperates with the tong member portions which extend beyond the outer sides of the ring 1. The rod 19 is mounted for movement with and relative to the tong members 9, being supported by a bracket 20 straddling the bush 6, and the upper ends 17 of the tong members are secured by bolts 21 or other suitable means to the plate 4. The rod 19 is guided axially in a hole in the top of the bracket 20 and is outwardly urged by a spring 22 to the position, illustrated in full lines in Figure 1, in which the tong members 9 are retained in closed position for insertion into or removal from the socket 12 of a glass insulator. The rod 19 is to be operated manually and is provided with a knob 23 which may be made of wood or any other suitable material.

The abutment 18 normally acts, as shown in full lines in Fig. 1, between the spring-urged upper ends 17 of the tong members but the opposed faces of the upper ends 17 are shaped so as to define a gap 24 between them which, when the rod 19 is depressed to displace the abutment 1S, easily accommodates the abutment 18 thus permitting the tong members to be subject to the sole control of the springs 16 so that the upper ends 17 move towards each other and correspondingly move apart the cavity form: ing ends of the tong members.

In operation, the structure on which the tong members are pivoted is manually superimposed on to a lower mould part 2, as illustrated in Figure 1, it being understood that, during this operation the abutment 18 is in its normal position in which the lower ends of the tong members are forced together as illustrated in full lines in Figure 1. When the structure has been superimposed on the mould part 2, pressure is applied to the knob 23 to move the rod 19 axially relative to the tong members so that the abutment 18 is moved into the gap 24. On the entry of the abutment 18 into the gap, as indicated at 180, Fig. l, the springs 15 swing the tong members about their pivot 13 so that the lower ends thereof move apart and against the wall of the sockets 12, as indicated in dotted lines 19a in Fig. 1, so that cavities are formed in the wall. To determine the extent of outward swing.- ing movement of the lower ends of the tong members under control or the springs 16, a stop 25 is provided for each of the tong members 9. As illustrated in the drawings, each stop comprises a set screw screwed through the bush 6 and retained in adjusted position by a lock nut 26. When pressure is relieved from the knob 23, the spring 22 returns the rod 19 so that the abutment 18 is again located in its normal position between the upper ends 17 of the tong members 9 and accordingly the lower ends thereof are again moved towards each other so that the structure can be removed from co-operation with the mould part 2.

Figures 4 and 5 illustrate an apparatus according to the invention which is intended to be arranged at a station of a machine for producing an insulator from a gob, the apparatus being automatic in operation and arranged, in known manner, for operation by an air cylinder the piston rod of which is indicated generally in Figure 4 by the reference numeral 27. The piston rod 27 operates in the Well known manner and is effective to cause operation of the apparatus according to the invention in synchronism with the usual pressing upper mould part, not shown. To this end the lower mould parts 2, Fig. 4 are, in known manner, mounted in a table and are rotated step by step to bring in turn each lower mould part successively to the gob feeding, pressing, cavity forming, and cooling stations.

In this embodiment of the invention, the plate 4 is spaced from and is movable relative to the locating ring 1, the plate 4 being mounted for movement along guide posts 28 secured to the locating ring 1 and extending upwards therefrom as viewed in the drawings. Also in this embodiment of the invention the tong members 9 are independently pivoted, being each mounted on a pivot 29 which extends through the limbs of a U-shaped bracket 30, which extends through an aperture in the plate 4, the brackets being secured to the support by bolts 31 or other suitable means. As can be seen from the drawings stops 25 are provided for each of the tong members 9.

The rod 19 is secured to a further plate 32 also movable along the guide posts 28 and compression springs 33, 34 extend respectively between the plates 4, 32 and the ring 1 and plate 4. The plate 32 is provided with stops constituted by rods depending from the plate 32 towards the plate 4.

Upstanding from the ring 1 are adjustable locating rods 36 for the support 4. The compression springs 34 tend to urge the plate 4 into engagement with heads 37 at the free ends of the rods 36 which latter pass through holes in the plate 4 so that the plate can be moved relative to the rods 36 in the direction of the axes thereof. The springs 33 are stronger than the springs 34, the ratio of loading being of the order of 5:1, for a purpose described below.

In operation, the structure on which the tong members are pivoted is, as stated above, actuated by the piston rod 27 when a lower mould part 2 is positioned beneath the apparatus, as illustrated in Figure 4. At the commencement of the downward movement of the apparatus towards the lower mould part, the relative positions of the parts of the apparatus are as shown in full lines in Figure 4 and the abutment 18 is in its normal position so that the lower ends of the tong members are in their closed position for insertion into the socket 12 of the insulator 3 in the lower mould part 2. During the downward movement of the apparatus the locating ring 1 becomes seated on the mould part 2 and is arrested thereby, whereupon continued downward movement of the piston rod 27 causes the plate 32 and the plate 4 to be moved relative to the ring 1, the pressure exerted by springs 33 overcoming the springs 34 so that the spacing between the stops 35 and plate 4 is maintained until collars 38 secured to the plate 4 for movement therewith engage bushes 39 secured to the ring 1. The bushes 39 have an internal diameter such that the springs 34, when compressed, are housed therein. When the collars 38 and bushes 39 abut, as indicated at 38a, 39, the plates 4 and 32 and abutment i8 occupy the positions indicated in chain line at 40, 32a and 13b and the lower ends of the tong members 9 are disposed in cavity-forming position relative to the socket 12 of the insulator 3 in the mould part 2, as indicated at ltib. Downward movement of the plate 32 is continued until it reaches the position indicated in dotted lines at 32b and this further movement of the plate 32 compresses the springs 33. Just as the stops 35 engage the plate 4, the abutment 18 is moved to the position indicated at 18c at which position it is displaced into the gap 24 so permitting the spring 16 to swing the tong members 9 about their pivots 29 and against the wall of the socket 12, as indicated in dotted lines at 100, Fig. 4, to form cavities therein.

On the return stroke of the piston rod 27 the plate 32 is moved upwards While the springs 33 retain the plate 4 in its lowermost position until collars 40 movable with the plate 32 engage locating nuts 41 on the guide posts 28 and the abutment 18 is returned to its normal position between the upper ends 17 of the tong members 9, thus causing the tong members 9 again to be moved angularly about their pivots 29 so that their lower ends are closed together ready for withdrawal from the socket 12. The continued upward movement of the plate 32 relieves the compression in springs 33 so that the springs 34 cause the plate 4 to move upwards towards the plate 32 until it is arrested by the heads 37 on the locating rods 36, after which the piston rod 27 is operative to lift the apparatus as a unit away from the mould part 2.

I claim:

1. Apparatus for forming cavities in the wall of the socket of a pin-type glass insulator whereby cement in the socket and surrounding the pin interlocks the pin with the insulator, comprising a locating ring settable on a lower mould part in which an insulator is formed, an apertured plate carried by the ring for movement therewith, tong-supporting means secured to said plate to extend through the aperture therein, a pair of tong members pivotally supported by said tong-supporting means for swinging movement and to extend beyond the opposite outer and inner sides of said ring, a swelling on each tong member on the outside of the end portion thereof which extends beyond the mould-engaging side of said ring, a spring to urge apart the tong member portions having said swellings, an abutment disposed for co-operation with the tong member portions extending beyond the side of the ring opposed to the mould-engaging side thereof, a rod carrying said abutment and supported for axial movement towards and away from said swellings thereby to permit and prevent sole control of the tong members by said spring, and adjustable stop means carried by said tong-supporting means to determine the extent of swinging movement of the tong members under control of the spring.

2. Apparatus for forming cavities in the wall of the socket of a pin-type glass insulator whereby cement in the socket and surrounding the pin interlocks the pin with the insulator, comprising a structure settable on a lower mould part in which an insulator is formed, a bush secured to said structure, a pair of tong members pivotally supported by said bush for swinging movement and to extend therethrough and beyond the inner and outer opposite sides of the structure, a swelling on each tong member on the outside of the end portion thereof which extends beyond the inner side of said structure, a spring to urge apart the tong member portions having said swellings, an abutment disposed for co-operation with the tong member portions extending beyond the outer side of said structure, a rod carrying said abutment and supported for axial movement towards and away from said swellings thereby to permit and prevent sole control of the tong members by said spring, and adjustable stop means carried by said bush for co-operation with the tong members to determine the extent of swinging movement of the tong members under control of the spring.

3. Apparatus for forming cavities in the Wall of the socket of a pin-type glass insulator whereby cement in the socket and surrounding the pin interlocks the pin with the insulator comprising a structure settable on a lower mould part in which an insulator is formed, a bush secured to said structure, a pair of tong members extend ing through said bush and beyond the opposite inner and outer sides of said structure, a pivot carried by said bush and supporting the tong members for swinging movement, a swelling on each tong member on the outside of the end portion thereof which extends beyond the inner side of said structure, a spring to urge apart the tong member portions having said swellings, a bracket stradciting the bush and tong members and secured to the outer side of said structure, an abutment disposed for co-operation with the tong member portions extending beyond the outer side of said structure, a rod carrying said abutment and guided by said bracket for axial movement to wards and away from said swellings thereby to permit and prevent sole control of the tong members by said spring, and adjustable stop means carried by said bush for cooperation with the tong members to determine the extent of swinging movement of the tong members under control of the spring.

4. Apparatus for forming cavities in the wall of the socket of a pin-type glass insulator whereby cement in the socket and surrounding the pin interlocks the pin with the insulator, comprising a locating ring settable on a lower mould part in which an insulator is formed, a rod supporting plate and a tong supporting plate carried by said ring for movement therewith, movement relative thereto, and for movement relative to each other along the axis of the ring, a pair of tong members pivotally supported by the tong member supporting plate for swinging movement and to extend beyond the opposite sides of said ring, a swelling on each tong member on the outside of the end portion thereof which extends beyond the mould engaging side of the ring, a spring to urge apart the tong member portions having said swellings, a rod depending from said rod supporting plate towards the tong member supporting plate, an abutment carried by said rod to co-operate with the tong member portions extending beyond the side of the ring opposed to the mould engaging side thereof thereby to permit and prevent sole control of the tong members by said spring, adjustable stop means carried by the tong member supporting plate to determine the extent of swinging movement of the tong members under control of said spring, a first spring means to space the rod supporting plate from the tong member supporting plate, a second spring means weaker than said first spring means to space the tong member supporting plate from said ring, first plate locating mean to locate the tong member supporting plate in relation to the ring along the axis thereof, second plate locating means to locate the rod supporting plate in relation to the tong member supporting plate and to the ring along the axis thereof, and stop means carried by the rod sup porting plate to determine the extent of relative move ment between the rod supporting and tong member sup porting plates during movement 'of the rod to permit control of the tong members by said spring.

5. Apparatus for forming cavities in the wall of the socket of a pin-type glass insulator whereby cement in the socket and surrounding the pin interlocks the pin with the insulator, comprising a locating ring settable on a lower mould part in which an insulator is formed, a rod supporting plate and an apertured tong supporting plate carried by said ring for movement therewith, movement relative thereto, and for movement relative to each other along the axis of the ring, a pair of U-shaped brackets secured to the tong member supporting plate and extendb ing through the aperture therein, a tong member pivotally supported by each said bracket to extend through the aperture in the tong member supporting plate and beyond the opposite sides of said ring, a swelling on each tong member on the outside of the end portion therof which extends beyond the mould engaging side of the ring, a spring to urge apart the tong member portions having said swellings, a rod depending from said rod supporting plate towards the tong member supporting plate, an abutment carried by said rod to cooperate with the tong member portions extending beyond the side of the ring opposed to the mould engaging side thereof thereby to permit and prevent sole control of the tong members by said spring, adjustable stop means carried by each said bracket to determine the extent of swinging movement of the tong members under control of said spring, a first spring means to space the rod supporting plate from the tong member supporting plate, a second spring means weaker than said first spring means to space the tong member supporting plate from said ring, first plate locating means to locate the tong member supporting plate in relation to the ring along the axis thereof, second plate locating means to locate the rod supporting plate in relation to the tong member supporting plate and to the ring along the axis thereof, and stop means carried by the rod supporting plate to determine the extent of relative movement between the rod supporting and tong member supporting plates during movement of the rod to permit control of the tong members by said spring.

6. Apparatus for forming cavities in the wall of the socket of a pin-type glass insulator whereby cement in the socket and surrounding the pin interlocks the pin with the insulator, comprising a structure settable on a lower mould part in which an insulator is formed, guide posts secured to the outer side of said structure, a rod supporting plate and an apertured tong member support-- ing plate each slidable lengthwise of said guide posts towards and away from said structure, a first set of compression springs surrounding the guide posts and extending between said plates, a second set of compression springs weaker than said first set, said second set of springs surrounding said guide posts and extending between said tong member supporting plate and said structure, locating members carried by said structure to determine the distance by which the tong member supporting plate can be moved away from said structure by said weaker springs, a pair of tong members pivotally supported by said tong member supporting plate for swinging movement and to extend through the aperture therein, a swelling on each tong member on the outside of the lower end portion thereof, a spring to urge apart the tong member portions having said swellings, an abut ment disposed for co-operation with the upper end portions of the tong members, a rod carrying said abutment and supported by said rod supporting plate for movement therewith to permit and prevent sole control of the tong members by said spring, adjustable stop means carried by said tong member supporting plate to determine the extent of swinging movement of the tong members under control of the spring, and stop means carried by the rod supporting plate to determine the extent of relative movement between the rod supporting and tong member supporting plates during movement of the rod to permit control of the tong members by said spring.

References Cited in the file of this patent UNITED STATES PATENTS 306,146 Gray Oct. 7, 1884 668,928 Parsons Feb. 26, 1901 1,502,561 Glaspey July 22, 1924 FOREIGN PATENTS 101,527 Germany Feb. 9, 1899 

